Ash collector



Feb. 18, 1947. E. w. BULLOCK 7 2,415,955

ASH COLLECTOR Filed Jan. 1, 1945 Q INVENTOR. El/Ls W. Bu//oc BY w A mew/Ev Patented Feb. 18, 1947 2,415,935 ASH coLLEc'ron Ellis W. Bullock, Birmingham, -Ala., assignor to Fly Ash Arrestor Corporation, a corporation of Alabama Application January 1, 1945, Serial No. 570,964 A This invention relates to an ash collector of the type associated with the chimney or flue from a solid, fuel fired furnace and has for an object the provision of apparatus of the character designated which shall be simple and economical of design, highly efiicient in operation, and which shall operate with a minimum of draft loss.

A still further object of my invention is to provide a fly ash collector adapted to be installed in the breeching section of a furnace flue which'shall occupy a minimum of space, and

embody a plurality of separating units enclosed within a single casing through which the gases from the furnace pass, and which shall be adaptedto separate the solid material from the gases of combustion with a maximum of efficiency and a minimum draft loss.

I In my prior Patent No. 2,348,785 dated May 16, 1944, and assigned to Fly Ash Arrestor Corporation; I have shown, described and claimed an ash collector comprising a plurality of horizontally disposed relatively small tubes mounted in a single casing and in each of the tubes is located a helicoid which imparts a spiral path to the gases and causes the solid particles to travel around the walls of the tubes. Slots are provided in the tubes through which the solid particles pass to fall to the bottom of the casing and be discharged. In the apparatus disclosed in my patent aforesaid, I employ a regularly formed right helicoid; that is, one in which the flight stands perpendicular to the axis of the pipe upon which the flightis mounted. Also, in that apparatus the flights preferably each made a complete turn aboutthe' pipe upon which they were mounted, or extended through an arc of 360. While the apparatus disclosed in my patent aforesaid has proved eminently satisfactory in operation, I have since discovered that the draft loss necessarily brought about by a collector of this type can be materially reduced without any sacrifice of efiiciency and even with an increase in efficiency by employing the apparatus herein disclosed.

' In accordance with my present invention, I provide a plurality of multiple flight helicoids,

I a vertical line, or a line vertical to the axis of the helicoid. I have found that this inclination of the helicoid flights aids in causing the solid particles to move outwardly of the helicoid, In-

stead of providing the casings of the helicoids with slots, I provide a plurality of irusto-conical separating members through which the gases pass after leaving the helicoid, and in which the solid particles separate from the gases and fall downwardly into the bottom of the collector casing. Another important feature of my invention is the provision of a transition at'the entrance end of each of the helicoid casings which changes it from a cylindrical casing to a rectangular one and all the rectangular helicoid casings are mounted in side by side relation at their entrance ends in the collector casing, so that there is a minimumof impedance to the flow of gases into the collector. Similar transitions are provided at the discharge ends of the frustoconical seprating elements, and the rectangular discharge ends thereof are mounted in the collector casing in a manner similar to that employed a the entrance ends of the helicoid casings. Each helicoid casing and its associated separating elementsare supported intermediate their ends by a plurality of relatively narrow bars to which they are appropriately joined, preferably by welding.

Apparatus embodying features of my invention is illustrated in the accompanying drawing, forming a part'of this application, in which Fig. 1 is an elevational view of the collector looking towards the entrance end;

Fig. 2 is a sectional view taken along the lines II-II of Fig. 1;

Fig. 3 is a detail sectional view showing the relation between the separating elements and the helicoid;

Fig. 4 is a diagrammatic elevational view showing my improved ash collector installed in association with a boiler furnace; and

'Fig. 5 is a detail view of one of the intermediate supports.

Referring now to the drawing for a better understanding of my invention, I show a rectangular collector casing l0 having a hopper bottom I I, in which casing are mounted a plurality of collector units [2. Each of the collector units comprises, at its entrance end, a helicoid casing [3 which is cylindrical in cross section the major portion of its length but which isprovided with a transition 14 at the inlet end which transforms it into a rectangular form where it is secured to the casing l0. As will be seen in Fig. 1, the several collector units are mounted in the collector casing in side by side relation, thereby minimizing the resistance to gas flow entering the collector casing.

Mounted within the collector casing H! in alignment with each of the helicoid casings 13 are a plurality of frusto-conical separating units l6, l1, and H3. The separating unit I8, at its discharge end, is provided with a transition is, changing it from a, cylindrical cross section to a rectangular cross section where it is connected to the casing at its discharge "end. The rectangular transitions 19 are connected in side by side relation at the discharge end of the collector casing II], as may be seen in Fig. 2 of the drawing. Each of the separator units is smaller in diameter at its entrance and than it is at its discharge end, and thereby leaving a separating space around each of the units between the discharge end thereof and the receiving end of its next adjacent unit. Also, it will be seen from Fig. 3 of the drawing, that the unit it is smaller in diameter at its receiving, or entrance end, than is the discharge end of the helicoid casing I3, leaving a discharge space 2| around the entrance end ofthe separator unit l6 and between it and the discharge end of the helicoid casing 13. The

. helicoid casing l3 and the separator units l6, l1

and 18 are supported intermediate the ends of the collector casing in by means of a plurality of bars 22, the bars each being notched at 23, 24 and 25 to fit snugly against the sides of the helicoid casing and the separating units, thereby holding them in their properlrelative positions. The bars 22 :are secured to the casing and the separating units by welding or other suitable means.

Mounted in each of the helicoid casings IS on the .pipe 26,:is a multiple flight helicoid 21. Each of theflights 28 of thehelicoid leans, or is oblique, to thelaxis of the pipe .26 upon which the helicoid is mounted. By this arrangement, the solid particles borne by the gases entering the helicoid casing flow around through the passageways between the helicoids over the inclined, curved surfaces thereof and in their flow over said surfaces there are created regions of low density on said surfaces and around thewalls of the helicoid casing toward which the solid particles migrate. I have found, with this design, that it is, not essential for the flights '28 to make a complete turn around the ,pipe 26 in order to effect the separation of the solid particles from the; gases, and that the draft loss is considerably reduced by stopping the flights short of a complete turn, I have found that where the flights are turned about the spine 2-6 through an arcof 270 I obtain the-maximum of efiiciency of separation with a minimum of draft loss. Furthermore, my improved ash collector does not .require .gas velocities of the order of those necessary with centrifugal collectors. I

In Fig. 4 of the drawing 1 show a boiler .fur nace 30 from which the gases of combustion pass through a flue 31. At 32 I show one of my improved ash collectors into which the. gases of combustion are discharged from the flue 3i. Ashes collected by the collector 32 are discharged into a suitable receptacle such as shown at 33.

From the foregoing description, the operation of my improved apparatus will be apparent. The gases of combustion bearing solid material such as fly ash enter into the-helicoid casing l3 and flow through the helicoidal passageways which causes the solid particles to move to the outer perimeter of the path-of flight as already described. 'I'have found that the helicoidalmotion imparted to the gases persists for some time and is pronounced throughout the passage of the gases through the separating units I6, I! and E8. The solid material borne by the gases being at the outer perimeter of the path thereof, passes through the openings 2| between the discharge ends of the helicoid casing [3, in the entrance ends of the separating units 16, and also passes outwardly through the spaces between the discharge ends of the separating units I6 and l1 and the entrance-ends of the separating units l1 and IS. The solid material thus passing out through the said spaces falls downwardly into the hopper bottom I l of the collector casing, from whence it is discharged as has already been explained. The helicoid casings l3 and the separating units I6, I1 and I8 are made of relatively thin sheet metal, as are the transitions l4 and I9, and the transitions are connected to the casing T0 and to each other in side by side relation, whereby there is a minimum of impedance to gas flow entering the collector casing.

From the foregoing it will be apparentthat I have devised an improved ash collector which is simple and economical of design, presents a minimum of impedance to flow of gases therethrough, and consequently operates with a minimum of draft loss, and one which afiords the maximum of separation of solid materials from the gases of combustion.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not 'so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is: g

1. In an ash collector of the character de scribed, a collecting unit comprising a single helicoid casing of substantially constant diameter through which the gases of combustion pass, a helicoid mounted in the casing and comprised of a helical flight mounted on an axial shaft, and a frusto conical separating unit disposed in alignment with the helicoid casing, said unit and said helicoid casing having their adjacent ends lying substantially in the same transverse plane to define an annular space between the discharge end of said helicoid casin and the entrance end of the separating unit.

2 In an ash collector of the character described, a collecting unit comprising a single helicoid casing of substantially constant diameter through which the gases of combustion pass, a helicoid mounted in the casing and comprised of a helical flight mounted on an axial shaft, said flights leaning with respect to the shaft in the direction of gas flow therethrough, a frustoconical separating unit mounted at the discharge end of the helicoid casing in alignment therewith and having its entrance endsmaller in diameter than the helicoid casing and disposed adjacent the discharge end of the helicoid casing in submounted at the discharge end of the helicoid casing in alignment therewith and having its entrance end smaller in diameter than the helicoid casing and disposed adjacent the discharge end of the helicoid casing in substantially the same transverse plane, thereby defining an annular separating space between the discharge end of the helicoid casing and the entrance end of the separating unit.

4. In an apparatus for collecting solids from the gases of combustion from a furnace, a collecting unit comprising a cylindrical casing through which the gases pass, a helicoid mounted in the casing comprised of helical flights mounted on a central axial shaft and having its flights leaning in the direction of gas flow therethrough, and a frusto conical separating element having a lesser diameter smaller than that of the cylindrical casing connected to the discharge end of the said casing in alignment therewith with the entrance end of the separating element and the discharge end of the casing lying in substantially the same transverse plane thereby defining an annular separating space.

5. In an apparatus for collecting solids from the gases of combustion from a furnace, a collecting unit comprising a cylindrical casing through which the gases pass, a multiple flight helicoid mounted in the casing comprised of helical flights mounted on a central shaft and having its flights leaning from 20 to 45 in the direction of gas flow to effect stratification of the solid matter in the gases, a series of frusto-conical separating members disposed in end to end relation with respect to each other with the first member of the series at the discharge endof the helicoid casing in alignment therewith, each of said separating members having its lesser diameter smaller than the discharge end of the helicoid casing and its greater diameter substantially that of the helicoid casing and each being disposed for the gases to flow therethrough from the lesser toward the greater diameter end thereof, the adjacent ends of the helicoid casing and its associated separating member and the adjacent ends of succeeding separating members lying in substantially the same transverse planes thereby defining a plurality of annular separating spaces, and a plurality of relatively narrow supporting members for holding the helicoid casing and separating members in alignment.

ELLIS W. BULLOCK.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 630,023 Baker Aug. 1, 1899 1,525,249 Mastenbrook Feb. 3, 1925 1,735,298 Pfefier Nov. 12, 1929 1,917,643 Goldkamp July 11, 1933 2,082,242 Bowen June 1, 1937 2,348,785 Bullock May 16, 1944 

